Power transmitter



Apri122, 1941. s. THOMPSON Em 2,239,633

POWER TRANSMITTER Filed NOV. 20, 1959 2 Sheets-Sheet 1 i mm]: il mlm, B

INVENTORS Charles ,5. T/wmpson By &. Philip 210mm ATTORNEYS.

April 1941- c. s. THOMPSON ETAL 2,239,633

POWER TRANSMITTER Filed Nov. 20, 1939 2 Sheets-Sheet 2 Patented Apr. 22, 1941 POWER TRANSMITTER Charles S. Thompson, Elmhurst, and Philip B. Clark, Chicago, Ill., assignors to Union Special Machine Company, Chicago, 111., a corporation of Illinois Application November 20, 1939, Serial No. 305,214

4 Claims.

This invention relates to driving units and power transmitters especially suitable for sewing machines and the like, and particularly driving units having a motor shiftably or movably mounted for the purpose of adjusting or maintaining effective its driving connection, to the'machine to be driven. The invention aims to provide a simple and reliable power unit; to facilitate and cheapen the manufacture of the unit; and to adapt the unit for easy installation under various conditions of use. Other features and advantages of the invention will appear from the following description of a species'or form of embodiment, and from. the drawings.

' In the drawings, Fig. 1 is an end view of the driving unit or transmitter applied to a sewing machine, parts of which are broken away or omitted.

Fig. 2 is a side View of the driving unit with certain parts in vertical longitudinal mid-section, also showing a portion of the sewing machine table to which the unit is attached.

Figs. 3, 4., and 5 are plan and perspective view of parts of the support of the driving unit; and Fig. 6 is a perspective view of 'an actuating lever for controlling the driving connection between the motor of the unit and the sewing machine.

In Fig. 1, the transmitter or driving unit is shown mounted beneath a sewing machine table III, and it drives the sewing machine II on said table through any suitable connection, such as coacting rotary driving members I2 and I3, associated with or forming part of the driving unit, and mounted onthe main drive shaft I5 of the sewing machine, respectively. As here shown, these driving members I2, I3 are V-grooved pulleys with an interconnecting belt I4. As shown in Figs. 1 and 2, the driving unit comprises an electric motor I6 whose shaft I1 is mounted in suitable bearings I8 (only one of which is shown) carried by one or both of the motor end 'bonnets I9, 20, which are preferably separate parts abutting endwise against the ends of the motor stator frame 2| and (removably) secured thereto by bolts or screws 22, only one of which appears in the drawings. The motor I6 is mounted for movement or shifting down or up relative to the supporting structure or table I0 associated with the sewing machine I I, for the purpose of properly maintaining the driving connectionformed by the belt I4 with sufficient pressure and friction to be eifective. To permit such movement or shifting of the motor I6 to tighten or loosen this driving connection, a supporting structure 25 attached to the motor I9 is pivoted orfulcrumed about an axis formed by a pivot pin 26 extending substantially parallel with the motor shaft I1 and the sewing machine shaft I5, to one side of the common plane of these shafts. As shown in Figs. 1 and 2, the pivot pin 26 extends through hinge lugs 21, 28 on parts 29 and 30, the former a bracket plate attached by bolts 3| tothe under side'of the table II), and the latter forming part of the motor support 25.

Preferably, the motor support 25 abuts and is secured endwise against one end, at least, of the motor I6; and as here shown, the motor support 25 has bracket portions 33 and 34 extending downward from its portion 30 above mentioned and abutting endwise against suitable surfaces on both ends of the motor I6: viz., as shown in Fig. 2, on the end bonnets I9 and 2D, to which these parts 33 and 34 are secured by bolts or screws 35.

Thus the support 25 is attached to the motor I6 quite independently of its stator frame 2 I, avoiding any necessity of providing brackets on said stator frame, or of drilling bolt or screw holes in its laminations (not shown). To the end bonnet.20 is also attached the supporting or fulcrum bracket means 36, here shown as integral projections from the bracket 34. On the bonnet I9, the abutting surfaces for the part 33 are provided by, projecting lugs or ears 3'I; whilefor the part 34, there is a shouldered annular seat 38,0n the bonnet 20, within which engages a correspondingly shouldered annular seat on said part 35. As shown in Figs. 1, 2, 3, 4, and 5, the motor support part 30 has the form, of a plate with the hinge lugs 28 projecting upward therefrom, and the brackets 33, 34 are separate parts removably secured to this plate. The bracket part 33 is curved in correspondence to the upper side of the motor I6 and has bosses 39 to takebolts or screws 4| which secure it to the part 30, while its ends are apertured to take the bolts 35 which secure it to the lugs 31 on the motor bonnet I9. The bracket 34 is of approximately circular general outline, corresponding to that of the end bonnet seat 38, and has an upstanding boss 42 to take a bolt 43 which secures it to the part 30. The bracket 34 may also carry a housing for the (lower portion of) rotary driving member I2 and the clutch hereinafter described: as here shown, this is formed by an annular reinforcing fiange 44 integral with the bracket 34. The lower portions of this flange 44 project to the right as the fulcrum brackets 36 already mentioned, for a purpose to be explained hereinafter.

When the parts 33, 34 are attached to the motor I6,'their bosses 39 and 42 and bolts 4|, 43

provide a three-point attachment of the motor to the plate 36, assuring a proper bearing of these bosses against this part 36, in spite of any slight irregularities of workmanship, or any variations of the positions of the bolts in their holes in the parts 33, 34. As shown in Fig. 3, the plate 30 has double sets of holes for the bolts M and 43, permitting attachment of the parts 33, 34 to either end of the plate 30, so that the motor I6 may be turned end-for-end as compared with the position shown in Figs. 2 and 3, when the conditions of installation make this desirable. This allows of locating the pivot pin 26'either in front of the motor shaft IT or behind it, as shown in Fig. 1.

For adjusting the motor support 25 and the motor I6 relative to the table II] and the sewing machine I I to tighten or loosen the belt I4, there may be a ring bolt 41 pivoted to the plate 29 by a pivot pin 48 mounted in hinge lugs 49 on said plate and provided with nuts 50 for engaging and clamping between them an apertured portion of the plate 30, shown in Figs. 1, 2, and 3 as com prising a slotted projection 5! on one edge of the plate 39. As here shown, the relative locations of the shafts I5, II and the pivot 26 are such that even in the absence of the adjusting bolt 41, the weight of the motor and the associated parts tends to tighten the belt I4 and hold it taut.

Besides the pulley I2 and the motor I6, the

power unit of the transmitter includes an interposed friction clutch 55, which serves as a means of operatively connecting the pulley I2 and the associated driving connection I4, etc., to the sewing machine I I and disconnecting them therefrom. To assist in controlling the operation of the sewing machine by means of the clutch 55, a brake mechanism for stopping the driven parts when the clutch is thrown out may be associated therewith, as described hereinafter. As shown in Fig. 2, the clutch includes a driving flywheel member 56 mounted on the motor shaft I1 and compelled to turn therewith by a key and key-way engagement indicated at 51. A spacing sleeve 58 may be interposed between the fly-wheel 56 and the inner race of the ball bearing I8, to transmit the end thrust of the member 56 directly to said ball bearing. As shown in Fig. 2, the fly-wheel 56 has a radial lubricant duct and reservoir whose outer end is normally closed by a screw plug 59. With the driving clutch member 56 coacts a driven clutch member 60 whose cylindrical hub 6| carries the driving member I2, rotatably mounted on the shaft II, and may be provided with an anti-friction journal bushing 62. This bushing 62 may preferably consist of oil or grease impregnated porous or spongy metal, such as marketed under the name of Oilite. The driven clutch member 60 may have a conical-surfaced friction liner 63 for engaging a corresponding conical surface on the driving clutch member 56, and may have a conically beveled (rout-er) braking surface 65. The flange 44 on the pant 34 substantially surrounds and houses the clutch 55 and the pulley I2, with reasonable clearance. In the enlarged outer end of the hub 6| is shown an anti-friction ball bearing 66, in whose inner race is mounted a thrust member 61.

As a convenient form of actuator for operating the clutch 55 and the brake mechanism above referred to, a rocking lever I0 is fulcrumed on the fulcrum bracket arms 36 of the motor support 25, about an axis extending substantially at right angles to the shaft I1, and formed by a pivot pin II, whose ends are mounted in the apertured ends of said bracket arms 36. This lever I0 extends along under the motor I6 substantially parallel with the shaft axis I1 and in the same vertical plane. As shown, the lever III has an extended bearing hub I2 mounted on the pivot pin II and engaging against one of the bracket arm 36, and a spacing sleeve I3 is interposed between this hub and the other bracket arm 36. The upper (right-hand) arm of the lever I0 is forked to accommodate (and anti-turningly engage) a fiatsided (hollow) end projection I4 on the thrust ,member 61, and it carries round-headed abutment bolts I6 for engaging said member 61 at either side of the projection I4, and of the axis of the shaft II. A lubricator I1 is mounted on the end of the hollow projection I4, to deliver oil therethrough into the interior of the hub 6I for lubricating the bearing surfaces of pants on the shaft IT.

The lower (left-hand) arm of the lever I0 carries brake block means I8 with acting face beveled in correspondence with the conical periphery of the coacting driven clutch member 60. As shown in Figs. 1, 2, and 6, there are duplicate brake blocks I8 at opposite sides of the lever I0 and of the axis of the shaft II, seated in vertical channels of a cross-head member I9 on the lever 10, and they are secured by square-headed bolts 30 extending through slots in said blocks. The lower arm of the lever I0 is :apertured at 8| for universal pivotal engagement or connection with an eye of an operating link-rod 82, to which is connected any suitable operating means (not shown), such as a foot treadle. Thus the operating connection for the actuator lever I0 can operate the lever in all normal relations of the support 25 and the motor I6 to the supporting structure I0. As shown in Fig. 2, a helical tension spring 83 is connected between the apertured left hand end of the lever I0 and an ear 84 attached to the motor I6: via, to a box-like extension of the end bonnet I9, which may house the motor starting and controlling means, not shown. The spring 83 acts on the lever III beneath the motor I6 to urge the brake blocks I8 against the periphery of the driven clutch member 60, and preferably exerts suflicient braking force to stop the driven parts quickly.

When it is desirerd to drive the sewing machine II, the operator actuates the operating means (not; shown) to pull downward on the rod 82 and depress the brake shoes I8 out of contact with the driven clutch member 60, and to push the member 60 to the left into engagement with the driving clutch member 56. When it is desired to stop the machine II, the operator has only to release the actuator 82, whereupon the spring 83 will automatically throw in the brake shoes I8 against the conically beveled periphery of the driven clutch member 60, thereby pushing this member 60 to the right to throw out the clutch 55 and stopping the driven parts. When it is desired to tighten or loosen the belt I 4, to take care of a difference or change of length, or to facilitate the removal or installation of a belt, the operator has only to loosen one or both of the nuts 50 and then swing the support 25 downward or upward about the pivot 26, finally retightening the nuts to hold the support 25 and themotor I6 fixed in their proper positions. The universally flexible connection of the link-rod 82 to the lever I0 allows the link-rod to operate effectively in all positions of the support 25 about its pivot 26 (within the range of adjustment afforded by the bolt 41 and nuts 50, 50), substantially unaffected by such shifting or adjustment of this support 25.

Having thus described our invention, we claim:

1. A driving unit for sewing machines and the like comprising a motor having a stator frame and separate end bonnets therefor, a rotary driving member with means for connecting it to drive the machine, and clutch means interposed between said motor and said driving member; means for mounting said motor on the supporting structure of the machine to be driven, for shifting movement relative thereto to tighten or loosen the driving connection between said driving member and said machine, including a motor support attached to said end bonnets independently of said stator frame; means for adjusting said motor support and motor relative to said supporting structure; an actuator for said clutch means mounted on said motor support, and thus moving with said motor relative to said supporting structure; and an operating connection for said actuator flexibly pivoted thereto .to operate the same in all normal relations of said support and motor to said supporting structure.

2. A driving unit for sewing machines and the like comprising a motor having a stator frame and a separate end bonnet therefor carrying a bearing for the motor shaft, a rotary driving member with means for connecting it to drive the machine, and clutch means interposed between said motor and said driving member; means for mounting said motor on the supporting structure of the machine to be driven, for

shifting movement relative thereto to tighten or loosen the driving connection between said driving member and said machine, including a motor support attached to said end bonnet independently of said stator frame; fulcrum-bracket means also attached to said end bonnet; means for adjusting said motor support and motor relative to said supporting structure; an actuator for said clutch means fulcrumed on said fulcrumbracket means; and an operating connection for said actuator flexibly pivoted thereto to operate the same in all normal relations of said support and motor to said supporting structure.

3. A driving unit for sewing machines and the like comprising a motor having a stator frame, a rotary driving member coaxial with the motor shaft, and clutch means interposed between said motor and said driving member; means for mounting said motor and driving member on the supporting structure of the machine to be driven, for shifting movement relative thereto to tighten or loosen the driving connection between said driving member and said machine, including a support movably mounted on the said supporting structure and abutting endwise against the motor and secured thereto, and also carrying the shaft bearings for the motor and said driving member;

,means for adjusting said support, motor, and

driving member relative to the aforesaid supporting structure; and an actuator for said clutch means movably mounted on said support and thus moving with the motor relative to the said supporting structure, with an operating connection for said actuator flexibly pivoted thereto to operate the same in all normal relations of said support and motor to said supporting structure.

4. A driving unit for sewing machines and the like comprising a motor and a rotary driving member, with interposed clutch means; means for mounting said motor on the supporting structure of the machine to be driven, for shifting movement relative thereto to tighten or loosen the driving connection between said driving member and said machine, including a plate pivoted to the supporting structure, and brackets bolted to said plate and abutting and secured endwise against the ends of said motor, said plate having bolt holes permitting said brackets to be interchanged and the motor to be thus turned endfor-end relative to the plate; means for adjusting said motor support and driving unit relative to said supporting structure; an actuator for said clutch means mounted on one of said brackets, and thus moving with said driving unit relative to said supporting structure; and an operating connection for said actuator flexibly pivoted thereto to operate the same in all normal relations of said support and motor to said supporting structure.

CHARLES S. THOMPSON. PHILIP B. CLARK. 

